Ink jet head driving device

An ink jet head driving device in which a plurality of ejection channels included in an ink jet head are divided into two or more groups, and the ejection channels included in the same group are driven together, comprising:

• a plurality of driving waveform generation portions that are provided so as to respectively correspond to a plurality of ejection channels included in any one group among the plurality of ejection channels, receive printing data and correction data, generate a driving signal of the ejection channels on the basis of the received printing data, correct a waveform of the driving signal by using the received correction data, and then output the corrected waveform to corresponding ejection channels and the ejection channels of the other groups adjacent to the corresponding ejection channels;
• a random number generation portion that generates a random number;
• a connection portion that connects the random number generation portion to the respective driving waveform generation portions such that a value of a random number generated from the random number generation portion is supplied to each of the driving waveform generation portions as correction data having a value independent for each of the driving waveform generation portions;
• and
• a pseudorandom number updating portion that updates a random number generated by the random number generation portion each time the group of the ejection channels which are driven together is changed.

An ink jet recording apparatus comprising:

• an ink jet head including a plurality of ejection channels;
• a printing controller which is structurally apart from the ink jet head;
• and
• cable wires connecting between the ink jet head and the printing controller,
• wherein the ink jet head further comprising:
• a driving waveform generation portions giving driving waveform to the respective ejection channels,
• a pseudorandom number generation portion that generates a pseudorandom number,
• a data reception portion which receive printing data from the printing controller via the cable wires;
• wherein the driving waveform generation portions change the driving waveform based on the received printing data and the pseudorandom number.

An ink jet recording apparatus comprising:

• a plurality of ink jet heads each having a plurality of ejection channels;
• a printing controller;
• and
• cable wires connecting between the ink jet heads and the printing controller,
• wherein the ink jet heads further comprising:
• a driving waveform generation portions giving driving waveform to the respective ejection channels,
• a pseudorandom number generation portion that generates a pseudorandom number,
• an initializing portion which initializes the pseudorandom number generation portion with an initial value,
• a data reception portion which receive printing data from the printing controller via the cable wires;
• wherein the driving waveform generation portions change the driving waveform based on the received printing data and the pseudorandom number, and the initial values of the plurality of print heads are different each other.